(20 U.S.C. 6301 et. seq.), as amended by this Act, from programs. authorized under the Elementary and Secondary Education Act. of 1965 (20 U.S.C. 6301 et seq.), as in effect on the day before. the date of enactment of this Act.
The efficacy of a vaccine is different from its effectiveness. It is dependent on several factors such as: 1  adherence to vaccine schedules. 2  the disease â some diseases have vaccines against them that perform better than for other diseases. 3  the strain of vaccine â some vaccine strains are more effective than others.
Influenza vaccine. Influenza vaccines, also known as flu shots or jabs, are vaccines that protect against influenza. A new version of the vaccine is developed twice a year as the influenza virus rapidly changes. While their effectiveness varies from year to year, most provide modest to high protection against influenza. They decrease the number of missed days of work by a half day on average.